Terry Moore
BATTLE OF THE BANDS
A catchy title on the report and/or display board is OK,
but you should include the actual investigation question
(see below) on the title page of the report.
Which rubber band of the same length but
varying widths will “shoot” the farthest when stretched?
Mrs. Moore
Science Fair Report
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Terry Moore
PROBLEM
Note: Section titles may be centered, but the paragraphs should NOT be.
This is the question you are investigating in your project. It should be stated in
question form. A well-stated question will indicate what you are doing to test the
question. In this problem, you can tell that I am going to shoot different widths of
rubberbands to see which goes farthest.
Which rubber band of the same length but varying widths will “shoot” the farthest
after being stretched?
PURPOSE
Why do you want to know? How will you use the results? This section is
optional, but it does add an A into the averaging process!
I am developing an enrichment activity for my science lessons on potential and
kinetic energy. I want to know if thick rubber bands or thin rubber bands will shoot
farther so that I can put more distance between students (for safety reasons).
RESEARCH
In order to make an educated guess (the hypothesis), you have to get educated.
Look for information to help you learn more about your topic. For this topic, I
“Googled” the term stretchiness. It led me to a better term, elasticity. Articles
about elasticity led me to further research on potential and kinetic energy, which I
used to form my hypothesis. Students should have 1/2 to 1-1/2 pages
summarizing what they learned.
Energy is defined in our textbook as the ability to do work. There are different
kinds of energy. For this experiment, two kinds of energy are the most important for my
project: kinetic energy and potential energy. Kinetic energy comes from motion, when
work is actually being done. An example of kinetic energy would be a rock rolling down
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a hill. The work being done is the rock rolling, or if it hits an object during its fall, the
effect it has on that object. In a domino run, the kinetic energy of a falling domino
causes the next domino to fall, which in turn causes the next domino to fall, and so on.
Potential energy is the ability to do work. A bowling ball held above the ground is not
doing any work, but it has the potential to do so. When the ball is released and the ball
drops, it makes a dent in the ground when it moves the dirt. The higher the ball is held
before it is dropped, the more work it can do and the deeper the dent it forms.
Energy is never lost, but it can be changed from one form to another. When a
roller coaster is pulled up a hill at the beginning of a ride, it is gaining potential energy.
As the coaster then goes down the hill, the energy is changed to motion, or kinetic
energy. The higher the hill (potential energy), the faster and farther the coaster can
move. As the coaster descends the hill its potential energy decreases and its kinetic
energy increases. Other energy conversions can occur, as when the chemical energy
stored in a battery is converted by a flashlight into light energy, or when a heater
converts electrical energy into heat energy.
A rubber band is at rest, or equilibrium, when it is unstretched. By stretching it,
potential energy is stored in a rubber band. The more the rubber band is stretched, the
more energy is stored in it. You can feel the energy stored in a rubber band as heat. If
you place a rubber band against your forehead, then stretch it, you can feel the energy
being stored in it as heat.
If a rubber band is stretched and released, it will return to its original length.
However, if you keep a rubber band stretched out for a long time, it will not be able to
return to its original length. If you stretch it too far, a rubber band will break. When
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elastic materials are stretched they can develop cavitations, which are small holes that
form in the material. Cavitations would be a problem in materials requiring strength
(e.g. wood, steel), but they can help elastic materials. The holes would expand or
shrink, which can allow the material to endure stresses that might otherwise break it.
HYPOTHESIS
This is an “educated guess” about what you think will happen in your experiment.
Students should use the If…then…format. To get an A or B for this part, a
student should also explain why.
If I stretch rubber bands of the same length (3-1/2 inches) but varying widths (1/2 inch,
¼ inch, 1/8 inch), then I think that the thicker rubber bands will fly farther when released.
Potential energy is stored in a rubber band when it is stretched. I think that a wider
rubber band, made of more material, can store more energy. The more potential
energy that an object has, the more kinetic energy is available.
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MATERIALS
List all materials needed to be able to do/duplicate the experiment, including
specific sizes, brands, etc. This is like listing the ingredients at the beginning of
a recipe.
•
Rubber bands of same length, different widths:
3½”x½“
3½”x ¼“
3 ½ ” x 1/8”
•
Ruler (12”/30cm)
•
Four books (2 science, 2 social studies)
•
Meter stick or metric measuring tape
•
Data collections sheet (see Fig. 1)
•
Masking tape
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Fig. 1
DATA COLLECTION SHEET
Experiments should generate measurable data. In some experiments, it might
be hard to figure out how to record data numerically. See me for help in this
area if you wish.
1/4 INCH
RUBBER
BAND
Rubber band
length (cm)
Distance
traveled (cm)
Rubber band
length (cm)
Distance
traveled (cm)
Rubber band
length (cm)
Distance
traveled (cm)
+ 0 cm
(equilibrium)
+ 5 cm
+ 10 cm
+15 cm
1/8 INCH
RUBBER
BAND
+ 0 cm
(equilibrium)
+ 5 cm
+ 10 cm
+15 cm
1/16 INCH
RUBBER
BAND
+ 0 cm
(equilibrium)
+ 5 cm
+ 10 cm
+15 cm
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PROCEDURE
Numbered steps should tell every step taken to do the experiment. Be very
specific. The first step will usually be to gather all the materials. When I grade
this section (worth double points), I will be looking for evidence of controlling the
variables. I will also be looking for evidence that the experiment was repeated for
a total of at least three trials, to test the reliability of the results.
1.
Gather all materials listed above and set up in a large, unobstructed area
(e.g. gym).
2.
Construct launching mechanism with books, ruler, and tape. (See Fig. 2)
Photos such as the one in Fig. 2 can help you illustrate difficult directions.
3.
Using the ½ inch rubber band, measure the length of the rubber band at
equilibrium (unstretched), using the metric side of the ruler. Record this
measurement in the +0 column.
4.
Hooking the rubber band to the end of the ruler, stretch the rubber band so
that the end is 5 cm beyond equilibrium. (e.g. if the rubber band at equilibrium
is 9 cm long, stretch it until the end of the rubber band reaches 14 cm).
5.
Release the rubber band.
6.
Measure and record the distance that the rubber band moved, measuring the
distance from the front of the launching mechanism to the farthest point of the
rubber band.
7.
Repeat steps four through six an additional three times, each time stretching
the rubber band 5 cm more than before and recording distance traveled.
8.
Repeat steps 3-7 for the ¼” and 1/8” rubber bands.
9.
Repeat the entire procedure two more times to check for reliability of results.
10.
Average and graph results of the data.
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Fig. 2
Rubber Band Launching Mechanism
1. Stack two textbooks (social studies, science) to provide height. Tape books to
surface to prevent slipping.
2. Lean a third book (reading) at an angle, with the base six inches behind the
stacked books. Tape a ruler to the side with the metric side on top. This will
provide a consistent launch angle.
3. Use a fourth book (any) to keep the rest from slipping, located 10 centimeters
behind the stacked books. Tape firmly to surface to keep the apparatus from
slipping. This will also help maintain the correct launch angle.
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RESULTS
This section is worth double. Summarize the data in your report.
The following represents the average of the results of shooting the three rubber bands.
9 cm
14 cm
"1/2
inch
"1/4
inch
"1/8
inch
19 cm
24 cm
29 cm
0
300
450
460
630
0
200
450
345
400
0
400
525
650
366
It is easier to compare the results in the following graph.
A graph of the results must be included to get an A in the results section. We will
cover computer graphing skills at school, but the graph does NOT have to be
computer generated…it can be hand-drawn and taped into the report.
Distance flown in centimeters
Shooting Rubber Bands
700
650
600
630
525
500
400
400
300
300
200
200
450
460
345
400
366
0
9 cm
14
cm
"1/4 inch
"1/8 inch
100
0
"1/2 inch
19
cm
24
cm
Stretched Length
9
29
cm
Terry Moore
CONCLUSION
This section tells whether or not a student’s hypothesis was correct. It is NOT a
bad thing if the experiment did not turn out the way it was predicted! A good
conclusion will confirm or deny the hypothesis AND will discuss why a student
thinks the results turned out like they did. It is also a good place to suggest
changes in the experiment, and/or other research that might be done.
Based on the results of my experiment, my hypothesis was incorrect. The results
were mixed, but for the most part, the thicker rubber bands did not fly farther than the
thin rubber bands. I’m not sure of the reason for this, but I think it may have something
to do with how easily thick and thin rubber bands can be stretched. I noticed that it was
harder to stretch the thick rubber bands, especially the longer stretches. Maybe instead
of storing energy when they’re being stretched, thick rubber bands might have to “work”
hard to stretch and create a lot of friction and heat. Maybe stretching causes more
energy being given off as heat instead of being stored as potential energy. I also
wondered if the “fatter” rubber bands were affected by air resistance since there was
more surface area. The thinnest (1/8 inch) rubber bands seemed to get limp and
“floppy” as they flew away instead of shooting through the air. I think the medium
rubber bands (1/4 inch) will work best for my enrichment activity.
During my experiment, I found myself wondering about changing my variable.
Instead of testing the thickness of the rubber band, maybe I could try the same
thickness of rubber band (1/4 inch), and see whether short (2-1/2 inch), medium (3 inch)
or long (3-1/2 inch) rubber bands would fly the farthest. Maybe I’ll try that next year!
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BIBILIOGRAPHY
Students will receive information on correct bibliography formats. It is important to identify all of
the resources of information. There should be at least three resources; at least one of these
should be an internet resource, but at least one of the resources should NOT be from the internet.
Students were expected to provide HARD COPIES of their research. (Print the internet info (note
the website URL), photocopy book/magazine information, print e-mails from “experts”, etc.)
These are in a separate science fair folder, NOT in the final report. I told students not to throw
away ANYTHING related to science fair until they received their graded reports.
Cooney, Dr. Timothy et. al. Science. Glenview, Ill.: Scott Foresman, 2000.
“Energy”, World Book Encyclopedia, vol. 6. Chicago: Field Educational Enterprises,
1987.
http://192.107.108.56/portfolios/l/lautz_s/Science%20Fair%Handbook/sampleclassexp.h
tml#Rubber%20band%20experiment
http://essc.calumet.purdue.edu/classroom_Activities/rubber, Jan. 1, 2003.
http://www.gmhsscience.com/problems/kineticpotential.htm
http://www.siu.edu/~perspect/00_fall/elasticity.html, Davis, Marilyn. “Elastic Math.”
Jan. 9, 2003.
ACKNOWLEDGEMENTS
It’s just polite to thank all the people who helped ….e.g. Mom for typing and
running you around, Grandma for helping cut letters, etc.
I would like to thank the students in my and Mr. Lindgren’s classes for conducting
the experiment to provide the data for this experiment and report. I also want to thank
Mrs. Koloszar for all the work she does to make science fair a successful venture at
Northwestern Elementary. I would like to thank all of the students who worked hard on
their own projects, as well as the parents who encouraged, assisted, and/or nagged ☺
the students throughout their projects.
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